int fibonacci()
{
    const int n = 10000000;
    int i;
    int tmp;
    int val;
    int prevval;

    val = 1;
    prevval = 1;

    for(i=0;i<n;i++){
        tmp = val;
        val = prevval + val;
        prevval = tmp;
    }

    return val;
}
